Malt beverages, such as beer, are sold in both small containers, such as bottles and cans, and large containers, such as kegs. The cans and bottles may be disposable, but the kegs are too expensive to discard and must be reused.
Most brewers sell more than one brand of malt beverage, therefore, they prefer to have the kegs marked permanently only with the brewery name and to use other means to identify the specific malt beverage in the container. Such other means may be labels that are attached to the container or caps that are used to cover the outlet of the keg; the caps bear labels or are imprinted with the name of malt beverage and other useful information.
The cap protects the outlet from dust, but it is not intended or needed to prevent the malt beverage from leaving the keg because the outlet which is usually surrounded by a flanged neck, known as a Barnes neck, is closed with a two way valve assembly of the type shown in the Golding U.S. Pat. No. 4,142,658.
The two way valve assembly which is normally maintained in a closed condition by springs can accidently open to release small amounts of liquid or gas when the container is severely jarred, such as can occur when it is dropped three feet or more on to a hard unyielding surface. When that occurs the escaping liquid or gas can blow the conventional cap off the Barnes neck and the identifying information is lost.
There is a need for a simple inexpensive cap that will both remain on the keg when the valve assembly accidentally opens and not interfere with the operation of the valve assembly.